Extracranial giant cell arteritis: A narrative review.

A systematic literature search was performed to summarise current knowledge on extracranial giant cell arteritis (GCA), i.e. large-artery involvement in patients with or without clinically apparent temporal arteritis (cranial GCA). Extracranial GCA is increasingly recognised, both in patients with cranial GCA and with solitary extracranial GCA, due to increased awareness among physicians and development of modern imaging modalities. The literature on the pathogenesis and histopathology of extracranial GCA is scarce. It is considered to be similar to cranial GCA. Patients with solitary extracranial GCA often present with non-specific signs and symptoms, although vascular manifestations, mostly secondary to stenosis, may occur. Due to the non-specific clinical presentation and low sensitivity of temporal artery biopsies, extracranial GCA is usually diagnosed by imaging. 18F-FDG-PET, MRI, CT angiography and ultrasound are used for this purpose. At present, the optimal diagnostic strategy is undetermined. The choice for a particular modality can be guided by the clinical scenario that raises suspicion of extracranial GCA, in addition to local availability and expertise. Extracranial complications in GCA consist of aortic aneurysm or dissection (mainly the ascending aorta), aortic arch syndrome, arm claudication and posterior stroke (although this is technically a cranial complication, it often results from stenosis of the vertebrobasilar arteries). Mortality is generally not increased in patients with GCA. Treatment of patients with solitary extracranial and those with extracranial and cranial GCA has been debated in the recent literature. In general, the same strategy is applied as in patients with temporal arteritis, although criteria regarding who to treat are unclear. Surgical procedures may be indicated, in which case optimal medical treatment prior to surgery is important.

Large-vessel vasculitis: interobserver agreement and diagnostic accuracy of 18F-FDG-PET/CT.

INTRODUCTION: (18)F-FDG-PET visualises inflammation. Both atherosclerosis and giant cell arteritis cause vascular inflammation, but distinguishing the two may be difficult. The goal of this study was to assess interobserver agreement and diagnostic accuracy of (18)F-FDG-PET for the detection of large artery involvement in giant cell arteritis (GCA). METHODS: 31 (18)F-FDG-PET/CT scans were selected from 2 databases. Four observers assessed vascular wall (18)F-FDG uptake, initially without and subsequently with predefined observer criteria (i.e., vascular wall (18)F-FDG uptake compared to liver or femoral artery (18)F-FDG uptake). External validation was performed by two additional observers. Sensitivity and specificity of (18)F-FDG-PET were determined by comparing scan results to a consensus diagnosis. RESULTS: The highest interobserver agreement (kappa: 0.96 in initial study and 0.79 in external validation) was observed when vascular wall (18)F-FDG uptake higher than liver uptake was used as a diagnostic criterion, although agreement was also good without predefined criteria (kappa: 0.68 and 0.85). Sensitivity and specificity were comparable for these methods. The criterion of vascular wall (18)F-FDG uptake equal to liver (18)F-FDG uptake had low specificity. CONCLUSION: Standardization of image assessment for vascular wall (18)F-FDG uptake promotes observer agreement, enables comparative studies, and does not appear to result in loss of diagnostic accuracy compared to nonstandardized assessment.

Vasculitis revealed by posterior stroke.

Posterior ischaemic stroke is relatively uncommon, and its occurrence should alert clinicians to possible uncommon underlying disease. We report a patient with occipital brain infarction. The combination of age, gender, general malaise and elevated erythrocyte sedimentation rate led to the clinical suspicion of giant cell arteritis. Vertebral artery vasculitis was confirmed by 18-FD G positron emission tomography, combined with CT angiography, and immediate immunosuppressive therapy was started. Symptoms of stroke should, in a particular clinical context, raise suspicion of giant cell arteritis.

Parameters related to a positive test result for FDG PET(/CT) for large vessel vasculitis: a multicenter retrospective study.

The purpose of this study was to identify clinical and laboratory parameters that may improve the effectiveness of the use of fluorodeoxyglucose positron emission tomography ((18)F-FDG PET)(/CT) for diagnosing large vessel vasculitis (LVV), and secondarily to assess the contribution of (18)F-FDG PET/CT in finding other diagnoses for patients without signs of LVV on the scan. A multicenter retrospective study of (18)F-FDG PET(/CT) scans performed between January 2000 and December 2009 for clinical suspicion of LVV was conducted. A total of 304 (18)F-FDG PET(/CT) scans were included, of which 62 (20%) were positive and 242 (80%) were negative for LVV. Univariate analysis showed that patients with a positive scan were older (65.9 ± 13.4 versus 58.6 ± 16.5 years, p = 0.002), were more frequently female (76% versus 55%, p = 0.002), more often had a history of temporal arteritis (10% versus 3%, p = 0.044), less frequently had artralgia (31% versus 67%, p = 0.000), and had higher thrombocyte counts (434 ± 161 versus 373 ± 168 × 10(9)/l, p = 0.049) and a higher erythrocyte sedimentation rate (ESR) (72.6 ± 31.0 versus 51.4 ± 30.5 mm/h, p = 0.001) than patients with a negative scan. In the multivariate analysis, only artralgia (OR 0.091; 95% CI 0.023-0.366) and ESR (OR 1.024; 95% CI 1.002-1.046) remained statistically significant predictors. The presence of artralgia is a statistically significant negative predictor and an elevated ESR a statistically significant positive predictor of LVV showing up on (18)F-FDG PET(/CT). A reliable prediction of the outcome of the scan, based on these two parameters, is not possible however. (18)F-FDG PET(/CT) allows early diagnosis of LVV and may discover occult inflammatory or neoplastic disorders.